PURPOSE: Previous studies suggest that external-beam partial breast irradiation (PBI) delivered twice a day can lead to increased adverse cosmesis (AC). The objective of our trial was to determine whether two regimens for PBI given once daily over 1 week resulted in acceptable AC to inform a phase III trial. METHODS: Patients age ≥50 years with invasive breast cancer or ductal carcinoma in situ, ≤3 cm in size treated by lumpectomy with negative axillary nodes were randomly assigned to external-beam PBI of 30 Gy or 27.5 Gy, each given in five fractions once daily. The primary outcome was AC (fair or poor) by photographic assessment at 2 years. Secondary outcomes included AC assessed by nurse at 2 years, by patient self-assessment at 3 years, and late toxicity. On the basis of a 17% risk of AC with whole-breast irradiation, the upper bound of a two-sided 90% CI, 23% was set as the tolerance margin (OPAR, ClinicalTrials.gov identifier: NCT02637024 ). RESULTS: In total, 142 patients were randomly assigned to 30 Gy and 139 to 27.5 Gy. The median follow-up was 5 years. The mean age was 65 years, and the mean tumor size was 1.2 cm. Both schedules met acceptability criteria by photographic assessment (AC, 12.1% [90% CI, 8.2 to 17.6] for 30 Gy and 15.2% [90% CI, 10.8 to 21.1] for 27.5 Gy) and by nurse assessment. AC by patient self-assessment exceeded the 90% CI for the 30 Gy regimen. At 5 years, 16 (11.3%, 90% CI, 7.6 to 16.4) patients treated with 30 Gy and eight (5.8%, 90% CI, 3.3 to 9.9) patients treated with 27.5 Gy were observed to have grade 2 or more late toxicity. CONCLUSION: According to the study design, 30 Gy and 27.5 Gy resulted in acceptable cosmetic outcomes. In light of recent studies, a lower dose was chosen for the phase III trial.

Medically inoperable Merkel cell carcinoma of the head and neck treated with stereotactic body radiation therapy: a case report Jie Wei Zhu, Lilian Doerwald-Munoz, Justin Wann-Yee Lee

Introduction The tracheostomy site and adjacent skin is at risk for recurrence in head/neck squamous cell cancer patients. The tracheostomy tube is an in situ device located directly over the tracheostomy site and may have clinical implications on the radiation dose delivered to the peristomal region. This study aimed to investigate this effect by comparing the prescribed treatment planning dose with the actual dose in vivo to the peristomal clinical target region. A retrospective, dosimetric study was performed with approval of the institutional research ethics board. Methods Fifteen patients who had received high-dose radiotherapy to the tracheostomy region with in vivo dose measurements were included. The radiation dose at the skin surface underneath the tracheostomy device was measured using an optically stimulated luminescent dosimeter (OSLD) and was compared with the prescribed dose from the radiation planning system. The effect of the tracheostomy flange and/or soft tissue equivalent bolus on the peristomal dose was calculated. Results and discussion Patients with tracheostomy equipment in situ were found to have a 3.7% difference between their prescribed and actual dose. With a tissue equivalent bolus there was a 2.0% difference between predicted and actual. The mean prescribed single fraction dose (mean = 191.8 cGy, SD = 40.18) and OSLD measured dose (mean = 194.02 cGy, SD = 44.3) were found to have no significant difference. However, with the flange excluded from the planning simulation (density = air) target skin dose deviated from predicted by an average of 55.3% (range = 12.4-72.9, SD = 22.5) and volume coverage was not achieved. Conclusion In summary, the tracheostomy flange acts like bolus with a twofold increase in the skin surface dose. Changes in the peristomal apparatus from simulation to treatment needs to be considered to ensure that the simulated dose and coverage is achieved.

Background: Cancers of the head and neck region are often characterized by locally advanced, non-metastatic disease. Standard treatments for advanced cervico-facial cancers of the skin or primary head and neck squamous cell carcinoma (HNSCC) include combinations of surgery, radiation and chemotherapy, which are associated with high rates of acute toxicity and complications. Stereotactic body radiotherapy (SBRT) has been shown to be a promising modality of treatment for this patient population in retrospective studies; to our knowledge, there are no prospective clinical studies evaluating the safety and efficacy of SBRT in these patients.Methods: This phase 2, single institution, single arm study aims to evaluate response rates to SBRT in older age patients with locally advanced HNSCC for whom primary surgery is not recommended or performed. The intervention is SBRT 45 Gy in 5 fractions given every 3–4 days. Toxicity, quality of life and patient outcomes will be recorded regularly up to 24 months after completion of SBRT.Discussion: For this patient population, SBRT may offer a shorter and more effective treatment than the current standard of care palliative regimens. If the study demonstrates that SBRT is safe and effective, then this may lead to randomized studies comparing conventional radiotherapy to SBRT for selected head and neck cancer patients.Trial registration: ClinicalTrials.gov Identifier:NCT04435938. Date registered: June 17, 2020.

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinomas (OPSCCs) with locally advanced progression are generally treated with curative intent concurrent chemoradiation. This case report of a 51-year-old female highlights the potential for locoregional control with complete pathologic response following primary stereotactic body radiotherapy (SBRT). Previous studies on SBRT for head and neck cancers report variable dose fractionation schemes and inconsistent volume contouring techniques, with most SBRT applications focused on recurrent or post-operative settings rather than definitive primary treatment. In this case, the patient initially presented with palpable left cervical lymphadenopathy. Diagnostic workup confirmed non-keratinizing invasive squamous cell carcinoma of the left base of the tongue, with strong p16 positivity. After declining standard curative intent treatment options, including chemoradiation, the patient later accepted a palliative SBRT regimen of 40 Gy in five fractions weekly, targeting the oropharynx and unilateral neck. The patient ultimately only received 32 Gy in four fractions. Follow-up imaging demonstrated significant tumor regression, but at five months, a palpable L neck mass remained. A subsequent selective neck dissection confirmed complete pathologic response with no residual carcinoma. The patient remained disease-free 68 months after treatment with minimal late toxicities. This case supports the feasibility of using SBRT as a definitive modality for HPV-related OPSCC, highlighting the potential for durable locoregional control with an acceptable toxicity profile. Given the growing interest in both treatment de-escalation for HPV-related OPSCC and the application of SBRT in head and neck cancers, this report suggests a promising, though preliminary, role of SBRT in selected patients.